Problems with an air-source heat pump installation: what can be claimed
The heat pump never reaches the temperature promised, the hot water runs out, the bill has not come down as the salesman said it would, the outdoor unit is disturbing the neighbours, or the installation was never registered. We explain what the law requires of the installer, what guarantee protects you, and how a claim is brought where there is finance involved.
What you are really contracting for
A heat pump contract is not the sale of an appliance. It is a mixed contract of supply and works: the company sells a heat pump, but it also designs the installation, sizes it for one particular house, carries it out, commissions it and leaves it in a condition to work and to be registered. That distinction underpins almost every claim, because it allows you to require not merely that the unit works, but that the whole installation does what it was contracted to do.
Where the client is a private individual contracting for their own home, the relationship is also a consumer one, with everything that brings: the statutory guarantee, the right of withdrawal, control over the terms of the contract, and the liability of the finance provider.
What the law requires of the installer
Installing an air-source heat pump is, in legal terms, altering a thermal installation. The Reglamento de Instalaciones Térmicas en los Edificios (RD 1027/2007, the regulations on thermal installations in buildings) applies to fixed heating, cooling and domestic hot water installations, and treats as an alteration — among other cases — the addition or modification of heating, cooling or hot water subsystems, the replacement of a heat or cold generator by one with different characteristics, and a change in the type of energy used or the introduction of renewable energy (art. 2 RITE). Replacing an oil or gas boiler with a heat pump falls squarely within that definition.
From that follow specific duties which clients rarely know about and which, where they have not been complied with, put you in a very strong position:
- A technical report or full design, depending on the output, signed by a qualified technician, with a calculation of the property’s demand. If nobody calculated the demand, the equipment was chosen from a catalogue rather than for the house.
- Execution by an authorised installation company and a certificate of the installation on completion.
- Registration of the installation with the competent body of the Comunidad de Madrid (the Madrid regional government). Without that registration the installation is not legalised, which bars access to grants and to municipal reductions in the IBI (local property tax) or the ICIO (tax on construction works), as well as complicating any sale of the property.
- Documentation and maintenance: user manual, instructions, and a maintenance contract where the regulations require one.
The first question we always ask. Were you given the certificate of the installation and proof of its registration? If the answer is no — and very often it is — the company has not finished performing its contract, even though the units are hanging on the wall. That changes the conversation: the argument is no longer about whether the equipment underperforms, but about a service that is missing.
The five problems that reach our office
1. The equipment is undersized
The house does not reach the set temperature on cold days, or the hot water runs out at the second shower. It is almost always a sizing problem: insufficient output, a small cylinder, or emitters — old high-temperature radiators — incompatible with a heat pump working at low temperature. That is a lack of conformity of the installation as a whole, not a defect in the appliance, and the person liable is whoever sized it.
2. The promised savings never appear
Here one has to be precise, because not everything a salesman says is legally enforceable. A general statement about savings is advertising; a specific figure put in writing in the offer, in the preliminary study or in the brochure you were handed does form part of the content of the contract and can be claimed on. That is why the first thing we ask for is all the sales material, not just the contract: the savings study with its figure in euros per year is usually in a PDF the client has kept without knowing what it is worth.
3. The installation is not legalised
Without a certificate or registration, the client is shut out of the grants the deal was sold on and is left with a problem when they want to sell or let. It is a breach of one of the installer’s obligations, and allows you to require them to complete it or to claim for the loss.
4. Poorly finished work and damage
Unsealed pipe runs through the façade, damp, lifted floors, a consumer unit that does not meet the standards, condensate badly drained. This is liability for the execution of the works (arts. 1544 et seq. of the Civil Code, Código Civil) and for the damage caused (art. 1101 CC).
5. Repeated breakdowns and no after-sales service
The same fault three times in one winter, or equipment out of action for weeks waiting for a part. The guarantee does not merely require repair: it requires it to be done within a reasonable time and without significant inconvenience to the client, with the company bearing the cost of carriage, transport, labour and materials, and also of removing and reinstalling where what was installed has to be taken out (art. 118 of the consolidated text of the General Act for the Protection of Consumers and Users). Where repair fails repeatedly, the door opens to replacement, to a reduction in price or to termination of the contract.
Noise from the outdoor unit and the community of owners
The outdoor unit is what generates conflict with the neighbours and with the community of owners, and there are two separate questions here.
Where it has been put. An owner may alter the installations within their own flat provided this does not impair the safety of the building, its structure, its configuration or its external appearance, and does not prejudice another owner, and they must give prior notice to whoever represents the community (art. 7.1 of the Ley de Propiedad Horizontal, the Commonhold Act). Hanging a unit on the façade or in the courtyard, both of which are common parts, alters the external appearance: it needs a resolution of the owners’ meeting. An installer who put one up without warning the client of this has a problem that is his, not the client’s.
Since the reform of the Ley de Propiedad Horizontal in force from 22 March 2026, the installation of common or private systems for harnessing renewable energy, expressly including air-source and ground-source heat pumps, may be approved at the request of any owner by the vote of one third of the members of the community representing, in turn, one third of the participation quotas (art. 17.1 LPH). And the community may not pass on the cost of the installation or of its upkeep to those who did not vote in favour. It is a very attainable majority, and it has defused a good part of the refusals that used to block these installations; it is worth putting the item properly on the agenda rather than installing first and arguing afterwards.
How much noise it makes. Neither the owner nor the occupier is permitted to carry on activities contrary to the general rules on nuisance activities, and the community may demand that they cease and, where appropriate, bring proceedings for an injunction (art. 7.2 LPH). Running alongside that is the noise legislation — Ley 37/2003 and whichever municipal by-law applies — with its limits and its administrative route through the town hall.
If you have been served with a demand over noise, do not simply take the unit down. First it is worth taking readings with a certified sound level meter and checking whether the level is due to a poor choice of location, to the absence of an anti-vibration mount, or to equipment that is not the one set out in the offer. If the problem comes from how it was installed, the cost of moving or soundproofing it falls on the installer, and that needs to be established before any money is spent.
The finance: why the lender is liable too
Most of these installations are paid for with a loan signed by the salesman himself in the client’s sitting room. That finance is not a separate contract: where the credit serves exclusively to pay for that installation and the two contracts form a commercial unit, it is a linked credit agreement (art. 29.1 of Ley 16/2011, on consumer credit agreements).
- If the consumer withdraws from the installation contract, they cease to be bound by the credit agreement, with no penalty (art. 29.2).
- If the goods or services were not delivered or do not conform to what was agreed, and the consumer has complained to the supplier without obtaining satisfaction, they may exercise those same rights against the lender (art. 29.3).
- The ineffectiveness of the consumer contract renders the credit agreement financing it ineffective too (art. 26.2 of the same Act), and any term requiring payment in cash if the credit is not obtained is void.
In practice this changes the case: if the installer has disappeared or is insolvent, the claim is brought against the finance company as well, and it is good for the money. That is why we insist on documenting the prior complaint to the installer: it is the requirement art. 29.3 imposes.
What can be claimed, and within what period
- That they bring the installation into conformity: repair or replace it, free of charge and without significant inconvenience, including removing what was installed and reinstalling it (art. 118 TRLGDCU).
- A reduction in price or termination of the contract with repayment of what has been paid, where repair fails, is impossible or is not carried out within a reasonable time.
- Damages: the electricity or oil you went on paying for, the repair of the damage caused, the cost of completing the registration (art. 1101 CC).
- Withdrawal where the contract was signed away from the company’s business premises: fourteen calendar days, and thirty where it was signed during an unsolicited visit to your home (art. 102.1 TRLGDCU). If you were not informed of that right in writing, the period is extended by a further twelve months (art. 105.1).
- Guarantee periods: three years from delivery for lack of conformity (art. 120.1 TRLGDCU) and five years in which to claim from the moment the defect becomes apparent (art. 124). Separately, five years for personal claims for breach of contract (art. 1964.2 CC).
How we handle it, step by step
All the paperwork, not just the contract
Offer, savings study, brochures, contract, finance, invoices, certificate of the installation and proof of registration. What decides these cases is usually in the sales material handed over beforehand.
Technical report
An engineer or qualified technician checks the actual sizing against the property’s demand, the state of the workmanship and, where there is a noise dispute, the sound level readings.
Claim against installer and lender
A burofax (certified letter with proof of its contents) setting out what is required and the time allowed, with a parallel notification to the company that provided the finance. This step is not a formality: it is the legal requirement for proceeding against the lender afterwards.
Complaints form and the consumer route
Where appropriate, a complaint to the consumer authorities of the Comunidad de Madrid, or arbitration if the company subscribes to it. It is quick and inexpensive, and whatever the company replies is useful later in court.
Court proceedings
Against the installer and, where appropriate, against the finance company, seeking termination or performance in conformity, plus damages. We tell you beforehand what it is realistic to ask for and what each scenario costs.
Frequently asked questions
I signed at home, with a salesman who turned up unannounced. Can I pull out?
If the contract was concluded in the context of an unsolicited visit to your home, the withdrawal period is thirty calendar days, not fourteen (art. 102.1 TRLGDCU). And if the company did not inform you of that right in writing, the period ends twelve months after the date on which the original period would have expired (art. 105.1). These are long periods: it is worth reviewing the contract even if some time has passed.
The salesman told me I would save about €1,200 a year, and I have not.
What matters is whether that figure appears in writing in any document from the company — offer, preliminary study, brochure, email — or was only a conversation. A documented figure forms part of the content of the contract and failure to meet it can be claimed on; a verbal promise, on its own, is very hard to prove. Look through what you were given: that piece of paper is frequently the most valuable item in the case.
The company that installed it has closed down. Am I left with nothing?
Not necessarily. If the installation was financed with a linked credit agreement, you may assert against the finance company the same rights you would have against the installer, provided that what was contracted for has not been delivered or does not conform and you first complained to the supplier without obtaining satisfaction (art. 29.3 of Ley 16/2011). There may also be a manufacturer’s guarantee on the equipment.
The community of owners is demanding that I take the unit off the façade.
Two things have to be looked at: whether the location affects a common part or the external appearance of the building, in which case a resolution of the owners’ meeting was needed (art. 7.1 LPH), and whether the demand is based on noise or nuisance (art. 7.2 LPH). It is also worth knowing that the installation of renewable energy systems, with air-source heat pumps expressly named, is now approved by one third of the owners holding one third of the quotas (art. 17.1 LPH). In many cases the answer is not to remove it but to move it or soundproof it, and the cost falls on the installer if they chose the location badly or failed to warn that permission was needed.
Is it worth going to the consumer authorities, or better to sue straight away?
It depends on the amount and on who the other side is. The consumer route is quick and free and, even where the company does not subscribe to arbitration, its reply — or its silence — goes into the case later. In matters of any size we run it alongside the formal demand, so that no limitation time is lost.
Where we work
Our office is in Villanueva de la Cañada, and we act regularly in Brunete, Villanueva del Pardillo, Valdemorillo, Quijorna, Majadahonda, Las Rozas, Boadilla del Monte, Pozuelo de Alarcón and the rest of western Madrid — detached-house country, where these installations are especially common. This page forms part of our civil law practice; see also solar panels, building and renovation contracts and consumer rights.
Tell us about your case
If the heat pump is not delivering what you were sold, if the installation has not been legalised, or if you are being pursued for a loan on equipment that does not work, tell us what you signed and what you were promised, with whatever paperwork you have kept. We study every case before taking it on, and we tell you frankly whether it has any prospect of success.
First consultation: quoted before we start.
28691 Villanueva de la Cañada (Madrid)